Flexural-torsional flutter of an aircraft wing with distributed parameters in subsonic flight mode

This article describes the problem of strength and reliability of the aircraft (AC) and its elements remain important for designers. In recent times, due to the increase in mass and size of the AC, as well as flight speed, these problems have acquired particular importance. In solving the above problems, an important role is played by correctly accounting for the influence of oscillations and deformations of the AC arising under the action of external loads. The aim of the study is to develop a methodology for solving the problem and an algorithm for establishing the critical speed of flexural-torsional flutter of a viscoelastic AC wing. The results showed that in the classical formulation, the problem of flexural-torsional steady-state flutter of a viscoelastic AC wing with distributed parameters in the subsonic flight mode is considered. The study revealed that the aerodynamic load obeys the hypothesis of stationarity of the flight mode. The relationship between stress and strain is described using the hereditary Boltzmann-Volterra integral. Resolving equations of flexural-torsional flutter are obtained based on the Lame equations, in a direct statement of the problem. The task is reduced to determining the critical speed of the aircraft wing. A transcendental equation with a complex outgoing parameter is obtained, which is solved by the Muller method. The developed algorithm allows you to build your own aircraft wing shapes taking into account the viscoelastic properties of the material. It is concluded that taking into account the viscous properties of the material allow increasing the critical speed to 15%.